The US Supreme Court has granted a petition for certiorari in a case challenging USEPA’s Mercury and Air Toxics Standards (MATS), which set new emissions standards for new and existing coal- and oil-fired power plants.  As reported here in April, the US Court of Appeals for the D.C. Circuit upheld the standards after they were challenged by several state attorneys general, labor groups, and industrial groups.  Although the challengers raised several issues for the circuit court’s consideration, the Supreme Court has limited its reviewto the following question: “whether the Environmental Protection Agency unreasonably re[f]used to consider costs in determining whether it is appropriate to regulate hazardous air pollutants emitted by electric utilities.”

The Supreme Court’s decision to review the case gives the petitioners another chance at relief from an USEPA-estimated $9.6 billion (in 2007 dollars) in increased annual compliance costs.